charles.harbert wrote:

Usually, backfire is caused by raw fuel being burned while the exhaust valve is
opened. Since we don't have an exhaust valve, but we do have a very hot exhaust
manifold, perhaps raw fuel/air is being pushed into the exh man after the
ignition is turned off due to the rotating inertia of the prop.  If you can turn
off the fuel before the ignition (just like a conventional a/c engine), it might
stop the problem.

Sounds right on to me Chuck. The carb is still letting fuel go in
unlike an EFI system that shuts off the fuel with the kill switch.

Paul Lamar
 
The Aircraft Rotary Engine Newsletter.              Powered by Linux.

http://home.earthlink.net/~rotaryeng/            http://www.linux.org